LCD panel of large cell gap tolerance and LCD projector using it

ABSTRACT

A LCD panel having the large cell gap tolerance includes: an LC (Liquid Crystal) having properties changed by input voltage and changing a transmittance rate change of light incident from the outside; electrodes for applying voltage to the LC; base plates on which the electrodes are formed, each base plate having an LC layer located at prescribed intervals to inject the LC between the electrodes; a split pattern or a floating electrode formed inside each electrode, changing voltage applied to the LC and compensating a cell gap change; and a micro-lens attached on one side of one of the base plates and gathering lights, which are incident from the outside, on a central symmetric line of the slit pattern or the floating electrode. The LCD panel of large cell gap tolerance and the LCD projector using it include LCD panels having large LCD cell gap tolerance.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an LCD panel of large cell gaptolerance and an LCD projector using it, and more particularly, to anLCD panel of large cell gap tolerance and an LCD projector using it, inwhich a brightness change in each gray level and a transmittance ratechange due to an alignment error are small by compensating a cell gapchange.

2. Background of the Related Art

Recently, an Liquid Crystal Display(LCD) projector is utilized in alarge display device for an HDTV or a large display device used for anannouncement conference such as a seminar because of being small in itsvolume and easily adjusted in its projection screen size. In general,the LCD projector includes dichroic mirrors for dividing white lightoutputted from a light source into red, green and blue lights colors,LCD panels for modulating the divided lights with the dichroic mirrorsand a projection lens for adding and magnifying lights outputted fromthe LCD panels.

A conventional LCD panel used in the LCD projector includes an LiquidCrystal (LC), of which properties are changed according to inputvoltage, pixel electrodes and a-common electrodes for applying the inputvoltage to the LC, and base plates on which the electrodes are formed.Furthermore, the base plates, on which the pixel electrodes are formed,further include TFTs (Thin Film Transistors) for applying/blockingvoltage to/from LC layers every pixel. Here, the TFT is most used in theLCD panel of the LCD projector as being easy in multi-gray and fastresponse.

However, such LCD panel shows different properties according to itsthickness. That is, according to the LCD panel thickness, a celltransmittance rate is changed small in high gray level but large in lowgray level. Additionally, the LCD panel brightness is gradually loweredbecause an aperture ratio is lowered when the resolution of the LCDpanel becomes gradually high.

Even though the LCD is manufactured by highly controlled processes, theLCD thickness is not uniform to depending on the position even in thesame LCD panel. Furthermore, the different LCD panel thickness causes adifferent thermal expansion to depending on the position (or point) inthe same LCD panel because the LCD panel receives lots of infrared raysand visible rays from the light source. For example, if there is adifference of temperature of 1° C. between glass base plates of the LCDpanel, the cell gap is changed about 0.1 μm.

FIG. 1 illustrates a cross-sectional view of an LCD panel on which aconventional microlens is attached.

As shown in FIG. 1, the LCD panel, on which the micro lens is attached,includes a first glass base plate 1, TFTs 2 and pixel electrodes 3formed on the first glass base plate 1, a second glass base plate 6formed in a predetermined interval from the first glass base plate 1, acommon electrode 5 directing the TFTs 2 and the pixel electrodes 3 andformed on the second glass base plate 6, an LC layer 4 filled with LCand formed between the pixel electrodes and the common electrode 5, anda micro lens 7 attached on an opposite side of the side the second glassbase plate 6, on which the common electrode 5 is attached.

The micro-lens 7 transmits light entering a BM(Black Matrix), a signalline or a scan line (, which are non-modulated areas) toward the pixelelectrodes and increase effective aperture ratio.

FIG. 2 illustrates a detailed cross-sectional view of the pixelelectrode of FIG. 1. A gate electrode 9 of the TFT 2 is connected to thescan line of the LCD panel, a source electrode 8 is connected to thesignal line of the LCD panel, and a drain electrode 10 is connected tothe pixel electrode 5 of the LCD panel.

An operation method of the LCD panel on which the micro lens is attachedwill be described as follows.

In case of a selection period of time:

If voltage of the gate electrode 9 connected to the scan line is largerthan that of the source electrode 8 connected to the signal line, aconnection resistance of a channel formed between the drain electrode 10and the source electrode 8 becomes small. Therefore, voltage of thesource electrode 8 connected to the signal line is formed between thepixel electrode 3 and the LC layer 4.

In case of a non-selection period of time:

If voltage of the gate electrode 9 connected to the scan line is smallerthan that of the source electrode 8 connected to the signal line, theconnection resistance of a channel formed between the drain electrode 10and the source electrode 8 becomes larger, and thereby the drainelectrode 10 and the source

electrode 8 are electrically isolated. Therefore, the LC layer 4 keepselectric charge accumulated during the selection period of time.

If root means square (rms) voltage, which is applied to the LC layer 4formed between the pixel electrode 3 and the common electrode 5, iscontrolled when linearly polarized light emitted from a polarizer (notshown) mounted on the outside of the micro lens 7 passes the LC layer 4through the micro lens 7, the polarized state of the light is changed.The LCD pixel brightness is changed by the changed light selectivelypassing the analyzer mounted to the outside of the first glass baseplate 1 of the LCID panel, and thereby the pixel brightness change asdata information.

Meanwhile, the LCD projector according to the prior arts, according toLC mode, uses a 90° TN mode in case of a transmission type, a paralleloriented ECB (Electric Controlled Birefringence) mode in case of areflection type, or a TN mode having a twist angle less than 90°.

Recently, the LCD panel used in the LCD projector shows resolution of0.7 inch XGA level and may show resolution of 0.5 inch XGA level in thefuture.

However, the conventional LCD, on which the micro lens is attached, andthe LCD projector using it has still several problems that thebrightness change in each gray level is large and the transmittance ratechange due to alignment error is large, and thereby the video quality isdeteriorated and the production yield is low. The problems will bedescribed in more detail, taking examples as follows.

FIG. 3 illustrates a graph showing a relative transmittance change ineach gray level of the LCD panel according to the cell gap of the priorart.

As shown in FIG. 3, G0 indicates the reference, so the transmittancechange is zero when the thickness is 4.0 μm, G1 indicates the relativetransmittance change when the cell gap is 4.4 μm, and G2 indicates therelative transmittance change when the cell gap is 3.6 μm. Therefore,because the cell relative transmittance change differs about 40% or moreaccording to the cell gap, the brightness change in each gray level isstill large.

Therefore, even though the conventional LCD panel, on which themicro-lens is attached, places the focus on the pixel electrode, thebrightness change in each gray level is large and the transmittance ratechange due to the alignment error is large, thereby deteriorating thevideo quality and lowering the production yield.

Meanwhile, the LCD projector using the conventional LCD panel, on whichthe micro lens is attached, also has the above problems that thebrightness change in each gray level is large, the transmittance ratechange due to the alignment error is large, thereby deteriorating thevideo quality and lowering the production yield.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an LCD panel of largecell gap tolerance and an LCD projector using it that substantiallyobviates one or more problems due to limitations and disadvantages ofthe related art.

An object of the present invention is to provide an LCD panel of largecell gap tolerance and an LCD projector using it, which can minimize atransmittance rate change in each gray level by compensating thethickness of the LCD panel, to improve the video quality and theproduction yield.

Another object of the present invention is to provide an LCD panel oflarge cell gap tolerance and an LCD projector using it, which canminimize a transmittance rate change due to brightness and alignmenterrors in each gray level by compensating the thickness of the LCDpanel, to improve the video quality and the production yield.

A further object of the present invention is to provide an LCD panel oflarge cell gap tolerance and an LCD projector using it, which minimize atransmittance rate change due to brightness and alignment errors in eachgray level by placing focus of a micro lens on a central symmetric lineof a slit pattern or a floating electrode and compensating the thicknessof the LCD panel, to increase the video quality and the productionyield.

A still further object of the present invention is to provide an LCDpanel of large cell gap tolerance and an LCD projector using it, whichcan minimize a transmittance rate change due to a cell gap change and analignment error using a side electric field property according to thecell gap change.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, anLCD (Liquid Crystal Display) panel having large cell gap toleranceincludes: an LC (Liquid Crystal) having properties changed by inputvoltage, the LC changing a transmittance rate change of light incidentfrom the outside; electrodes for applying voltage to the LC; base plateson which the electrodes are formed, each base plate having an LC layerlocated at prescribed intervals to inject the LC between the electrodes;a slit pattern or a floating electrode formed inside each electrode,changing voltage applied to the LC and compensating a cell gap change;and a micro-lens attached on one side of one of the base plates, themicro lens gathering lights, which are incident from the outside, on acentral symmetric line of the slit pattern or the floating electrode.

In another aspect of the present invention, to achieve these objects andother advantages and in accordance with the purpose of the invention, anLCD projector includes: dichromatic filters for dividing light outputform a light source into red, green and blue colors; LCD panels formodulating the lights by minimizing a transmittance rate change of thelights output from the dichromatic filters by compensating a value thatmultiplies a anisotropic refractive index(Δn) of LC and d(cell gap) inrelation to a cell gap deviation in a gray level condition; and aprojection lens for gathering and magnifying the lights output from theLCD panels.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings;

FIG. 1 illustrates a cross-sectional view of a conventional LCD panel onwhich a microlens is attached;

FIG. 2 illustrates a detailed cross-sectional view of a pixel electrodeof FIG. 1;

FIG. 3 illustrates a graph showing a relative transmittance change ineach gray level of the conventional LCD panel according to the cell gap;

FIG. 4 illustrates a cross-sectional view of an LCID panel, on which amicro-lens is attached, according to a first preferred embodiment of thepresent invention;

FIG. 5 illustrates a detailed cross-sectional view of a pixel electrodeof FIG. 4;

FIG. 6 illustrates a view showing a structure of an equivalent circuitof a slit pattern of FIG. 4;

FIG. 7 illustrates a graph showing a relative transmittance change ineach gray level according to the cell gap of the LCD panel, on which themicro-lens is attached, according to of the present invention;

FIG. 8 illustrates a view showing a relative transmittance change due toalignment error of the micro-lens;

FIG. 9 illustrates a cross-sectional view of an LCD panel using amicro-lens according to a second preferred embodiment of the presentinvention;

FIG. 10 illustrates a detailed cross-sectional view of a pixel electrodeincluding a floating electrode of FIG. 9; and

FIG. 11 illustrates a view showing a structure of an LCD projector ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 4 illustrates a cross-sectional view of an LCD panel, on which amicro-lens is attached, according to a first preferred embodiment of thepresent invention.

As shown in FIG. 4, the LCD_(Liquid Crystal Display) panel, on which themicro-lens is attached, includes a first glass base plate 11, TFTs 12,pixel electrodes 14 and slit patterns 15, which are formed on the firstglass base plate 11, a second glass base plate 18 formed in apredetermined interval from the first glass base plate 1, a commonelectrode 17 directing the TFTs 12 and the pixel electrodes 14 which isformed on the second glass base plate 18, an LC(Liquid Crystal) layer 16filled with LC between the pixel electrodes 14 and the common electrode17, and the micro-lens 19 attached on an second glass base plate 18.Here, the micro-lens 19 is positioned opposite side of the commonelectrode 17 with reference to the second glass base plate 18 is.

FIG. 5 illustrates a detailed cross-sectional view of the pixelelectrode of FIG. 4.

A gate electrode 21 of the TFT 12 is connected to a scan line of the LCDpanel, a source electrode 20 is connected to a signal line of the LCDpanel, and a drain electrode 22 is connected to the pixel electrode 14of the LCD panel. Furthermore, the slit pattern 15 formed in the pixelelectrode 14 is designed in such a manner that a cross-sectional centerof a light spot 23 passing the micro-lens 19 is located at the center ofthe slit pattern 15, i.e., a point where an X-axis symmetric line and aY axis symmetric line of the slit pattern meet with each other. Here, acentral symmetric line of the slit pattern 15 is a symmetric line, whichdivides the slit pattern 15 into two in a longitudinal direction.

An operation method of the LCID panel according to the present inventionwill be described as follows.

First, referring to the drawings, when voltage is applied to the LClayer, the relationship between an electric field induced to the siltpattern 15 and a voltage 5 distribution will be described as follows.

FIG. 6 illustrates a view showing a structure of an equivalent circuitof the slit pattern of FIG. 4.

As shown in FIG. 6, V1 and V3 indicate voltage formed on the pixelelectrodes, and V2 indicates voltage formed on the common electrode. Atthis time, 10 assuming that there is a microelectrode at a part A in theslit pattern, C1, C2 and C3 indicate capacitances formed among the pixelelectrodes, the common electrode and the microelectrode.

Therefore, induction voltage_(V(A)) induced to the microelectrode(A) ofthe slit pattern is obtained through the following equation(1):V(A)=C 1 V1+C 2 V2+C 3 V3+. . . /C 1 +C 2+C 3+. . .   (1)

In the relationship between the voltage distribution_(V1, V3; V1=V3)induced to the microelectrode of the part A and the voltage distributionof the pixel electrodes, if the voltage distribution_(V1, V3; V1=V3)induced to the microelectrode of the part A is different from thevoltage distribution of the pixel electrodes, the horizontal electricfield of voltage corresponding to a difference between the voltagedistribution(V1, V3; V1=V3) induced to the microelectrode of the part Aand the voltage distribution of the pixel electrodes is applied betweenthe microelectrode of the part A and the pixel electrode.

In the relationship between the cell gap change and the inductionvoltage distribution, the V(A) moves toward the voltage distribution ofthe common electrode because the capacitance_(C2) between themicroelectrode and the common electrode is increased if the cell gap isreduced, and the V(A) moves toward the voltage distribution of the pixelelectrode because the capacitance_(C2) is lowered if the cell gap isincreased. That is, if dielectric anisotropic(A C) of LC is positive anda lateral electric field and a vertical electric field are applied atthe same time, liquid crystal molecules increase a strength orientedhorizontally if the lateral electric field becomes strong, but increasea strength oriented vertically if the lateral electric field becomesweak.

In the relationship between the cell gap change and LC anisotropicrefractive index (Δn), LC anisotropic refractive index (Δn)is increasedbecause the horizontal electric field is increased if the cell gap_(d)is reduced, but reduced because the vertical electric field is increasedif the cell gap is increased.

Therefore, the cell transmittance is proportional to a value thatmultiplies anisotropic refractive index (A n) of LC and the cellgap_(d). If one of anisotropic refractive index (A n) of LC and the cellgap_(d) is increased, the other is reduced because anisotropicrefractive index (A n) of LC and the cell gap_(d) are acted in oppositedirections to each other. Therefore, the transmittance rate change ofthe LCD panel according to the cell gap change is reduced because thevalue that multiplies anisotropic refractive index (A n) of LC and thecell gap_(d) is changed small.

FIG. 7 illustrates a graph showing a relative transmittance change ineach gray level according to the cell gap of the LCD panel, on which themicro lens is attached, according to the present invention. G10 is agraph showing the transmittance rate change in case that a referencecell gap is 4.011 m, G11 is a graph showing the transmittance ratechange in case that the cell gap is 4.4 Fun, and G12 is a graph showingthe transmittance rate change in case that the cell gap is 3.6 μm.

The following table 1 shows the maximum transmittance rate when the cellgap is changed ±10% in case that a diameter of light spot gathered on asymmetric central line of the slit pattern through the micro-lens is 4μlike the width of the slit pattern, and the width of the pixel electrodeis 4 μm.

TABLE 1 Graylevel 32 64 96 128 160 192 224 256 Maximum 16.4 4.2 8.2 14.115.5 17.8 15.4 3.1 Brightness change (%)

As shown in the drawing, the width of the transmittance rate changeaccording to the cell gap deviation of the LCD panel, on which the microlens is attached, of the present invention is narrower in each graylevel than that of the conventional LCD panel of FIG. 3. That is, theLCID panel, on which the micro-lens is attached, according to thepresent invention is reduced in the alignment error and minimized in thelight transmittance rate change.

FIG. 8 illustrates a view showing a relative transmittance change due toalignment error of the micro lens in a gray level 96 of FIG. 7. Thegraph shows the relative transmittance rate that the transmittance ratewithin the range of light spot radius of 2 μm is integrated every pointof 0.25 μm from the central symmetric line of the slit pattern.

For example, assuming that at a point x away from the central symmetricline and an integrated value of the transmittance rate of the lightpoint radius of 2 μm from x is I(x), the integrated value of thetransmittance rate of radius of 2 μm from the point 1 μm away from the xis I(x+1), and thereby the relative 5 transmittance rate(R(x)) isobtained by the following equation (2).R(x)=I(X+1)/I(X)X100  (2)

Therefore, the relative transmittance rate change due to the alignmenterror is smallest when light passing the micro lens is incident on thecentral symmetric line of the slit pattern. That is, because an effectof the slit pattern is not shown when the light passing the micro lensis separated from the slit pattern, the micro lens is designed in such amanner that the micro lens places the focus on the central symmetricline of the slit pattern.

Meanwhile, the slit pattern is designed in such a manner that the widthof the slit pattern is smaller than the cell gap because the operationvoltage is increased and the light and dark contrast ratio is lowered ifthe width is increased. For example, if the cell gap is about 4 μm, theoperation voltage is lowered and the light and dark contrast ratio isincreased only when the width of the slit pattern is 4 μm. Therefore, tomake the light, which passed the micro-lens, satisfy the aboveconditions and pass the slit pattern, the light must be located within 2μm from the central symmetric line.

FIG. 9 illustrates a cross-sectional view of an LCD panel using amicro-lens according to a second preferred embodiment of the presentinvention.

As shown in FIG. 9, the LCD panel, on which the micro lens is attached,includes a first glass base plate 11, TFTs 12 and pixel electrodes 14,which are formed on the first glass base plate 11, floating electrodes15-1 formed inside the pixel electrodes 14, a second glass base plate 18formed in a predetermined interval from the first glass base plate 11, acommon electrode 17 directing the TFTs 12 and the pixel electrodes 14,which is formed on the second glass base plate 18, an LC layer 16 filledwith LC between the pixel electrode 14 and the common electrode 17, anda micro-lens 19 attached on an opposite side of the side of the secondglass base plate 18. Here, the micro-lens 19 is positioned opposite sideof the common electrode 17 with reference to the second glass base plate18.

FIG. 10 illustrates a detailed cross-sectional view of the pixelelectrode including the floating electrode of FIG. 9.

A gate electrode 21 of the TFT 12 is connected to a scan line of the LCDpanel, a source electrode 20 is connected to a signal line of the LCDpanel, and a drain electrode 22 is connected to the pixel electrode 14of the LCD panel. Furthermore, the floating electrode 15-I formed in thepixel electrode 14 is designed in such a manner that a cross-sectionalcenter of a light spot 23 passing the micro-lens 19 is located at thecenter of the floating electrode 15-1, i.e., a point where an X axissymmetric line and a Y axis symmetric line of the floating electrode15-1 meet with each other. If the floating electrode 15-1 is designed tosatisfy the above conditions, the transmittance rate change due to thealignment error is minimized like the slit pattern 15 of the firstembodiment.

Meanwhile, because of the structure of the pixel electrode and themicro-lens, if the focus of the micro lens is not placed on the pointwhere the symmetric lines of the X axis and the Y axis meet with eachother, the focus is placed on one point of the central symmetric line.

In the LCD panel, in which the floating electrode 15-1 is formed insidethe pixel electrode, voltage induced to the floating electrode isinduced like the above equation 1 relative to the LCD panel, on whichthe slit pattern is formed, of the first embodiment. That is, becausethe floating electrode serves as the microelectrode (A) of the slitpattern of the first embodiment, the capacitance formed between thesurrounding electrodes is equal to that formed between themicroelectrode and the surrounding electrodes in an equivalent circuit.

Therefore, in case that there is the floating electrode, because voltageinduced to the floating electrode is moved toward voltage of the commonelectrode if the cell gap is reduced, the horizontal electric field isincreased, and thereby the cell refraction anisotropy is increased. Tothe contrary, because voltage induced to the floating electrode is movedtoward voltage of the pixel electrode if the cell gap is increased, theanisotropic refractive index (A n) of LC is reduced.

The cell brightness is a function of a value that multiplies anisotropicrefractive index (A n) of LC and the cell gap_(d). Here, because thecell refraction anisotropy_(Δn) and the cell gap(d) act in oppositedirections to each other, the LCD panel including the floatingelectrodes formed on the pixel electrodes operates like the LCD panelhaving the slit pattern of the first embodiment. That is, thetransmittance rate of the LCD panel including the floating electrodes isinsensible to the cell gap change.

Therefore, the LCD panel, on which the micro lens is attached, accordingto the present invention can reduce the alignment error generated whenthe micro-lens is attached. Furthermore, the LCD panel according to thepresent invention can minimize the transmittance rate change bydesigning in such a manner that the focus of the micro lens is placed onthe symmetric point of the slit pattern or the floating electrode.Thereby, the LCD panel can have improved color uniformity, color purityand color reproducibility.

Till now, the LCD panel according to the present invention is describedin relation to the embodiments having the slit pattern and the floatingelectrode formed on the first glass base plate, but the slit pattern andthe floating electrode may be formed on the common electrode. At thistime, in case that the slit patterns or the floating electrodes areformed in the pixel electrodes, they are simultaneously formed when thepixel electrodes are formed. However, in case that the slit patterns orthe floating electrodes are formed on the common electrode, a step ofexposing the common electrode is added.

The LCD panel constructed as the above may be utilized as an LCD elementof an LCD projector requiring high brightness and quality likeconference data or HDTVs.

FIG. 11 illustrates a view showing a structure of the LCD projector ofthe present invention. The LCID projector includes a light source 40generating and outputting white light, diachromatic filters ordiachromatic mirrors 41 r, 41 b-1, 41 b-2 and 41 g receiving the whitelight and dividing the white light into red, green and blue lights LCDpanels 42R, 42G and 42B for modulating (i.e., controlling thetransmittance rate) and outputting the red, green and blue lights,refraction mirrors 43 1 and 43-2 for regulating a optical path of thelights, and a projection lens 44 receiving and magnifying the lightspassing the LCD panels 42R, 42G and 42B and outputting the magnifiedlights to a screen 45.

Here, as described above, the LCD panels 42R, 42G and 42B place thefocus of the micro-lens on the center of the slit patterns or thefloating electrodes formed on the pixel electrodes.

Therefore, the LCD projector according to the present invention can haveexcellent color uniformity, color purity and color reproducibilitydisplayed on the screen.

The forgoing embodiments are merely exemplary and are not to beconstrued as limiting the present invention. The present teachings canbe readily applied to other types of apparatuses. The description of thepresent invention is intended to be illustrative, and not to limit thescope of claims. Many alternatives, modifications, and variations willbe apparent to those skilled in the art.

1. An Liquid Crystal Display (LCD) panel having large cell gaptolerance, the LCD panel comprising: a first glass base plate, on whichTFTs and pixel electrodes are formed; a second glass base plate apartfrom the first glass base plate with a predetermined distance, on whichcommon electrodes are formed; a Liquid Crystal(LC) filled between thefirst glass base plate and the second glass base plate, wherein, the LCis nematic liquid crystal material in which dielectric anisotropic (Δε)of LC is positive, such that the LC changes a transmittance rate changeof light incident from the outside by input voltage: micro-lens attachedon the second glass base plate, the micro-lens is positioned oppositeside of the common electrode and gathers light incident from theoutside; and a slit pattern formed in the pixel electrodes with apredetermined size such that a light spot formed by the micro-lens islocated at the center thereof and passes therethrough, the slit patternchanges the input voltage applied to the LC and compensates a cell gapchange.
 2. The LCD panel according to claim 1, wherein the slit patternis etched in the pixel electrodes to be a rectangular shape, whereinfocus of the micro-lens is placed on the center of the slit pattern. 3.The LCD panel according to claim 1, wherein the slit pattern furtherincludes a floating electrode etched to be floated therein, whereinfocus of the micro-lens is placed on the center of the floatingelectrode.
 4. The LCD panel according to claim 1, wherein the micro lensis in the form of a hexagon.
 5. An LCD projector comprising: dichroicfilters for dividing light outputted form from a light source into red,green and blue lights; LCD panels for modulating the divided lights byminimizing a transmittance rate change of the divided lights outputtedfrom the dichroic filters by compensating a value that multipliesanisotropic refractive index(Δn) of Liquid Crystal (LC) and a cell gapin relation to a cell gap deviation in a gray condition a projectionlens for gathering and magnifying the modulated lights outputted fromthe LCD panels; and, reflection mirrors for reflecting the lightsoutputted from the dichroic filters and the LCD panels to the projectionlens; wherein each LCD panel includes: a first glass base plate, onwhich TFTs and pixel electrodes are formed; a second glass base plateapart from the first glass base plate with a predetermined distance, onwhich common electrodes are formed; a Liquid Crystal (LC) filled betweenthe first glass base plate and the second glass plate, wherein the LC isnematic liquid crystal material in which dielectric anisotropic (Δε) ofLC is positive, such that it changes the transmittance rate change ofthe lights incident from the outside by input voltage; micro-lensattached on the second glass base plate, the micro-lens is positionedopposite side of the common electrode and gathers light incident fromthe outside; and a slit pattern formed in the pixel electrodes with apredetermined size such that light spot formed by the micro-lens islocated at the center thereof and lasses therethrough, the slit patternchanges the input voltage applied to the LC and compensates cell gapchange.
 6. The LCD projector according to claim 5, wherein the slitpattern is etched in the pixel electrodes to be a rectangular shape,wherein focus of the micro-lens is placed on the center of the slitpattern.
 7. The LCD projector according to claim 5, wherein the slitpattern further includes a floating electrode etched to be floatedtherein, wherein focus of the micro lens is placed on the center of thefloating electrode.
 8. The LCD projector according to claim 5, whereinthe micro-lens is in the form of a hexagon.